Tap changer



May 27, 1930. L, MMLEAN 1,759,991

TAP CHANGER Filed June 2, 1927 2 Sheets-Sheet l IIIIIIIIIII "1222!!! avwenkw May 27, 1930. M. L. M LEAN 1,759,991

. I TAP CHANGER Filed Jun 2, 1927 2 Sheets-Sheet 2 nozutw altozuu s Patented May 27, 1930 UNITED STATES PATENT OFFICE MARGARET LEE MACLEAN, F NILES, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS. TO

AMERICAN BROWN BOVERI ELECTRIC CORPORATION, OF NEV YORK, N. Y., A COR- PORATION OF NEW YORK TA]? CHANGER Application filed June 2, 1927.

This invention relates to improvements in tap changers for transformers such as are adapted to be employed in places exposed to the weather.

An object of the invention is the provision of improved contact devices whereby the tap connections of the transformer may be changed.

Other objects will appear as I proceed with the description of that embodiment of the invention which, for the purposes of the present application, I have illustrated in the accompanying drawings, in which:

Fig. 1 is a central vertical sectional view g of a tap changer showing a small fragment of the transformer tank to which the tap changer is applied;

Fig. 2 is a plan view, partly in section, on the line 2-2 of Fig. 1;

Fig. 3 is also a plan view, partly in section, on the line 3-3 of Fig. 1;

Fig. 4 is an elevational view showing the inner side of one of the contacts;

Fig. 5 is a plan view of the contact shown in Fig. 4;

Fig. 6 is a sectional plan view taken substantially on the line 6-6 of Fig. 1 and showing the parts on a larger scale;

Fig. 7 is a detail elevational view of a shoe carrier;

Fig. 8 is a plan view of the carrier illustrated in Fig. 7;

Fig. 9 is an inside elevational view of one r of the shoes employed for bridging the inclividual members of a pair of contacts; and

Fig. 10 is an end View of the shoe, looking in the direction of arrow 10, Fig. 9.

Similar reference characters refer to like parts throughout the views.

In the drawings. a fragment of a tank for enclosing a transformer is indicated at 10 and is shown provided with an opening 11 surrounded by an upstanding flange 12. Above the flange 12 is an annular gasket 13,

J u a serving to exclude moisture from the tank when the cover 14 is applied and clamped down by means of stud bolts 15 threaded into the tank and provided with heads which engage slotted projections 16 on the cover, as illustrated in Fig. 2.

Serial No. 195,974.

The cover 14 is provided with a pair of integral stops 17 and 18 and may have markings A and B on its upper surface to indicate different positions of adjustment of the tap changer, as will presently appear. The cover 14 has a central holetherein surrounded by an upstanding threaded flange 21. R0- tatably mounted in this flange 21 is a metal shaft 22 enlarged below the cover 14 and bored out to receive snugly the upper end of a rod 23 of insulating material, these two parts being fastened together by suitable means as by a pin 24.

The rod 23 has secured thereto one or more carriers 25, shown in detail in Figs. 7 and 8, there being two illustrated herein. They are identical in form but one is inverted with respect to the other. Each of these carriers 25 has at one extremity a split clamp 26 which is provided with a pair of holes 27 extending through both jaws of the clamp. Corresponding holes are provided in the rod 23 and bolts 28 are inserted and drawn up to secure the carrier to the rod.

These carriers each have one or more sockets 29, preferably two as shown, with a small hole 30 extending into the carrier from the bottom of each socket. The hole 30 receives a dowel or pilot 31 integral with or mounted in a boss 32 on a contact shoe 33, and the socket 29 receives a coil spring 34 tending to sepa rate the shoe 33 from its carrier 25. The shoe 33 is provided with vertical. ribs 35 near its side edges which overlap the side edges of the carrier 25 and thus insure the movement of the shoe with the carrier when the latter is rotated, as will presently be described.

A tube 36 of fiber or other insulating material is suspended from the top of the tank 10 by means of a plurality of hangers 37 which are attached to the tanlr by machine screws 38 and to the tube 36 by screws or the like.

On the inner wall of the tube 36 I mount contacts 40 which are preferably in the form of segments of a. cylinder roncentric with the tube 36. These contacts are arranged in pairs with the two contacts of each pair spaced apart vertically. Each of the contacts 40 is provided at one end with an. integral stud 41 which projects through a hole in the tube 86 and is threaded to receive a nut 42 by means of which the contact is clamped to the tube.

This stud 41 serves not only as a securing means for the contact but also as a binding post, a second nut being provided as ameans for clamping the wire lead or tap to the contact. At the end of the contact opposite the stud ll I provide a countersunk hole 1, and a hole drilled through the tube 36 to register therewith, these holes receiving a bolt 45 as an additional means for holding the contact firmly in position. The two contacts of each pair are preferably reversed so that the binding posts may be separated. as much as possible. In the form here illustrated there are four pairs of contacts l0, but a change in the number of these pairs involves merely a matter of design, as will be obvious.

The lower end of the rod 23 mounted for rotation in a bearing 16 which is carried by a bracket t? having flanged ends 18. Bolts 49 extend through aligned openings in tle flanges 48 and in the tube 36' to hold the bracket 47 in place.

Packing surrounds the shaft 22 at the upper end of the flange 21 on the cover 1- 1. be-

held in place by a packing gland 5O threaded onto the flange 21.

A. handle is secured to the shaft 22 by a pin 52 has a depending skirt 53 which extends down around the packing gland and nearly to the surface of the cover 1%, acting as watershed or moisture deflector. At one point on the shirt 53 there is a projection 54 which is steel to engage one or the other of the stops 17 and 18.

In the embodiment of the invention which is here disclosed, I have shown two positions only of the operating handle, four pairs of contacts 40, two contact shoes Without departing from the spirit of the invention, however, the number of handle positions may be increased and the number of shoes 33 pairs of contacts 40 may be either increased or decreased, depending upon requirements. The handle 51 is located out side the tank 10, and its movement from position A to osition i) is an operation which may be perf ned almost instantly. Any tendency of the shoes 33 and the contacts 40 to separate, due to sudden surges of current in the line to which the transformer connected,

absorbed by the springs 34, which immediately return the shoes to their contact position and sults.

lVhile in the drawings attached hereto, I have illustrated but one set or pair of shoes and cooperating contacts'therefor, it obvious that the lengths of the tube 36 and the rod 28 may be increased and the switch apparatus duplicated to whatever extent may be desired. For instance, if it should. be desired to apply the invention to three phase no out of adjustment condition remay be specified. in the appended claims.

having thus described my invention, I

claim a tap changer, a supporting tube,

-; mounted upon said tube and arpairs with. the individual contacts r spaced apart longitudinally of the "l pairs being spaced apart transthe tube, a metallic shoe adapted to contacts of a pair, a rod arranged iiv within said tube and mounted for roi secured to said rod, means for shoe upon said carrier so as .n 'ted motion therebetween, a lugs, one in transverse alignment contact, said tending to shoe and carrier, and means said rod. so as to move said shoe cm or 'a e ent with one pair of contacts into on with a different pair of contents.

I- a tap changer, a supporting tube. contacts mounted upon said tube and arranged in pairs with the individual contacts of a pair space-fl apart verticall said pairs being arranged at the same ere *ation and spaced at; .it herizontally,two meta ic shoes adapted to bridge the contacts of a pair, a rod d axially within said tube and mounted for rotation, a pair of carriers each having rod g portions at one end thereof.

:ne of said shoes upon each of said cars, and means for rotating said rod so as to move said shoes from' engagement with certain pairs of contacts into engagement with rent pairs of contacts.v

-.n a changer, supporting tube, ontacts mom 1. upon said tube and ar- 'r with individual contacts of apart vertica ly. said pair's betwo metallic bridge the contacts of win-in said two carriers 2: one end with a rod engaging of sad carriers being inverted other. means for support- 5 resiliei :ay upon each of o permit of limited inocl nea. s for rotating e said shoes from en 'rs of contacts into not pairs of contacts.

hair so to 4. in a tap changer, a supporting tube, a

pair of contacts mounted on the inner wall of said tube and spaced apart longitudinally thereof, a metallic shoe adapted to bridge said contacts, a rotatable rod arranged within said tube parallel to the axis thereof, a carrier formed at one end with a rod-engaging clamp, means for supporting said shoe upon said carrier to one side of said clamp, and means for rotating said rod so as to move said shoe into or out of engagement with said contacts.

5. In a tap changer, a supporting tube, a pair of contacts mounted upon the inner wall of said tube and spaced apart longitudinally thereof. a. metallic shoe adapted to bridge said contacts, a rotatable rod arranged within said tube parallel to the axis thereof, a carrier arranged upon said rod and engaging therewith through less than one-half its circum'lerence, a continuation of said carrier having means for securing the same to the rod. means for supporting said shoe upon said carrier proper, and means for rotating said rod so as to move said shoe into or out of enzasrementwith said contacts.

6. In electric switch apparatus. an operatino member su ported for rotary movement. and circuit malrine and-breakinQ, means associated with said member and including similar complementarv parts fitted on said member in reverse and in s aced relation with respect to each other. adiacentportions of said parts beinq disposed axially along the same portion of said member.

7. In electric switch apparatus. an operatinc. member su orted for rotarv movement. and circuit malrinmandbreaking means associated with said member and including similar complementarv parts f tted on said member in reverse and in spaced relation with respect to each other and provided with enlarrred h ea d. portions secured to said member, adiacent portions of said parts being disposed axiallv along: the same portion of said member and falling short of the respective head portions.

8. In electric switch apparatus. a tubular casing of insulating material, contacts disposed interiorly of said casing and fixed directly to the inner wall thereof in spaced relation with respect to each other. an actuating rod of insulatine material disposed interiorly and centrally of said casing and supported for rotarv movement about its own axis, a carrier fixed directly to said rod. a contact shoe disposed between said carrier and said contacts for sliding movement thereon into and out of bridging relation with respect thereto, means forming respectively part of said carrier and said. shoe and cooperating to connect said shoe to said carrier for rotary movement therewith while providing for free relative movement of said carrier and shoe in a direction radially of said rod, and means interposed between said carrier and said shoe and operating to urge the latter MARGARET LEE MAoLEAN.

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